non-blocking io, EINTR

[Mark Linn]

On Wed, Feb 27, 2008 at 5:25 AM, James Bailie <jimmy at mammothcheese.ca> wrote:
> Mark Linn wrote:
>
>   > I am setting the O_NONBLOCK flag on a socket file descriptor using fcntl,
>   >
>   > will a read() on the socket return EINTR when the process get a signal?
>
>  By default, read() will restart itself automatically, regardless
>  of whether the socket is blocking or not, as long as there is
>  data to be read in the socket receive buffer.  You can change
>  this behavior by calling sigaction().  For example, the code
>  below will make SIGTERM interrupt system calls.  They will return
>  an error code, usually -1, with the global errno set to EINTR.
>  If the socket is non-blocking and the socket receive buffer is
>  empty, then read() will also return an error, but with errno set
>  to EWOULDBLOCK.
>
>  #include <signal.h>
>
>  struct sigaction sigact;
>
>  sigact.sa_handler = sigterm_handler;
>  sigemptyset( &sigact.sa_mask );
>  sigact.sa_flags = 0;
>
>  if ( sigaction( SIGTERM, &sigact, NULL ) < 0 )
>  {
>     perror( "sigaction()" );
>     exit( 1 );
>  }
>
>  --
>  James Bailie <jimmy at mammothcheese.ca>
>  http://www.mammothcheese.ca
>

Thanks, Ed and James,

Then why in the world the sample code in this acm paper would test
EINTR in read and write?

link is here.

http://delivery.acm.org/10.1145/1350000/1344155/9815.html?key1=1344155&key2=2950393021&coll=GUIDE&dl=&CFID=15151515&CFTOKEN=6184618